Method in the utilizing of tobacco waste

ABSTRACT

Tobacco waste is mixed with a liquid, such as water in the weight proportions 3:1 - 3:7 between tobacco and liquid, and the mixture is subjected in a preferably closed container to blow, pressure, or shock impulses of a high repetition frequency, for forming substantially water dissoluble lumps. The water dissoluble parts of these lumps are subsequently dissolved in a liquid such as water. The solution thus formed is separated from at least the principal portion of the tobacco material which is indissoluble in water, for forming an adhesive which consists principally of tobacco and water and is particularly intended for the manufacture of artificial tobacco.

[ Aug. 7, 1973 i 1 METHOD IN THE UTILIZING 0F TOBACCO WASTE [75]Inventor: Erik Arne Wallberg, Jonkoping,

Sweden [73] Asslgnee: Industrielaboratoriet Aktienbolag,

.lankoping, Sweden [22] Filed: Dec. 30, 1970 21 Appl. No.: 102,879

Related U.S. Application Data [63] Continuation of Ser. No. 712,158,March 11, 1968,

FOREIGN PATENTS OR APPLICATIONS 871,952 7/1961 Great Britain 131/140 RPrimary Examiner-Melvin D. Rein Attorney-Cushman, Darby & Cushman [57]ABSTRACT Tobacco waste is mixed with a liquid, such as water in theweight proportions 3:1 3:7 between tobacco and liquid, and the mixtureis subjected in a preferably closed container to blow, pressure, orshock impulses of a high repetition frequency, for forming substantiallywater dissoluble lumps. The water dissoluble parts of these lumps aresubsequently dissolved in a liquid such as water. The solution thusformed is separated from at least the principal portion of the tobaccomaterial which is indissoluble in water, for forming an adhesive whichconsists principally of tobacco and water and is particularly intendedfor the manufacture of artificial tobacco.

5 Claims, 1 Drawing Figure abandoned.

[52] U.S. Cl 131/140 C [51] int. Cl A24b 3/14 [58] Field of Search131/17, 140-444 [56] References Cited UNITED STATES PATENTS 3,203,4328/1965 Green et al. 131/140 C 3,194,245 7/1965 Clarke 131/140C 3,353,54111/1967 Hind et a1. 131/140 C METHOD IN THE UTILIZING OF TOBACCO WASTEThis application is a continuation of my earlier application Ser. No.712,158 filed on Mar. 11, l968 now abandoned, relating to a method inthe utilizing of tobacco waste which arises e.g. in the manufacture ofsmokables.

A known method of utilizing coarser waste tobacco particles is to remixthem directly into the tobacco which is being prepared in themanufacture in question. In order to prevent said particles from endingup in the smokers mouth, the smokables are usually provided with afilter.

Furthermore, it is known to utilize finer waste tobacco particles bymixing them with a suitable binder and then form the mixture e.g., intoa sheet. It is also known to secure waste tobacco particles by means of.

an adhesive or binder directly on uncut tobacco leaves or the like whichare then utilized as constituents of smokables. A binder of the kind inquestion generally consists of a cellulose derivative, made of cellulosefrom some kind of wood. Even although it is possible to make cellulosefrom tobacco and suitable derivatives thereof, this is seldomeconomically profitable on account of the fact that the cellulosecontents of tobacco are very low (about 12 percent). With any kind ofbinder, however, the tobacco waste has to be disintegrated insubstantially dry condition before the forming of the web comprised oftobacco waste and binder or before the application of the tobacco wasteonto tobacco leaves.

In addition thereto, wet grinding of tobacco waste is also known. In sodoing, tobacco is ground in the presence of water in the proportions 1:6l:l2 by weight, i.c., about one part of tobacco to nine parts of wateruntil a suspension of fine tobacco particles in water is formed. Aftersuitable treatment and the addition of a suitable ingredient, such ascarboxymethylated cellulose (CMC) it is possible to form sheets,filaments and webs of the suspension or to spray it e.g., onto tobaccoleaves.

The present invention is based on the surprising discovery that tobaccowhich is disintegrated and treated in a preferably closed container andin a suitable way can be dissolved to a very considerable extent inwater, or a liquid principally consisting of water, for forming anadhesive or binder which may be used in the first instance for theutilization of tobacco waste. The characteristic features of theinvention reside therein that the weight proportions tobaccozliquid liein the range 3:1 3:7 and in that the mechanical treatment in the form ofshock impulses of a high repetition frequency created throughcooperation between a rotary member and abutments in said container iscontinued until substantially water dissoluble, chip-like, horny lumpsor the like are formed, the water dissoluble parts of which aresubsequently dissolved in an additional quantity of liquid which iscomprised of substantially pure water, after which the solution isseparated from at least the biggest ones of the undissolved residualpieces of said tobacco lumps, for forming an adhesive which consistsprincipally of tobacco and water.

The invention also encompasses tobacco adhesives or binders which havebeen manufactured by means of the above method, and semi-manufacturedtobacco articles which have been made with the utilization of the abovetobacco binder as well as smokables which contain such semi-manufacturedarticles.

In the drawing the single FIGURE illustrates a tendency curve of thedissolubility of tobacco in water.

In the manufacture of the tobacco adhesive according to the inventiontobacco waste is mixed with water or a liquid principally consisting ofwater in the approximate proportions 3:2 by weight, i.e., about twoparts by weight of water to three parts by weight of tobacco waste. Inthis specification the expression a liquid principally consisting ofwater refers to ordinary domestic tap water which may contain glycol,glycerine or alcohol as well as recirculated tobacco particles orpieces, as is specified in the following disclosure. The object aimedat, i.e., that at least the principal portion of the tobacco waste isdissolved in the water after the treatment is achieved, even if theproportions should differ somewhat from those stated above, but thecontents of water should preferably be within the range of one third tohalf of the total weight of the mixture of tobacco and liquid. In anycase, the weight proportions of the tobacco and the total amount ofliquid (water) shall be within the range 3:l 3:7. This amount of watercan be absorbed by the tobacco, as is well known to those skilled in theart. The wet tobacco is then subjected to a heavy mechanical treatment,e.g., chopping, beating, crushing, grinding, rolling, kneading or thelike, which is preferably carried out in a closed space, since the waterotherwise would evaporate and the tobacco becomes dry ground which doesnot give the desired effect. A laboratory defibrator is a grinding orrefining apparatus of a suitable kind. The grinding is, in this case,brought about by four wings (a cross on a spindle) which rotate in acircular cylindrical container having a closure and a bottom. Thecircular shape is interrupted by ridges or counter-edges which aresecured to the circumferential wall of the container and project aboutone mm above the cylindrical wall. The counter' edges have no realgrinding effect, but the tobacco accumulates ahead of the wings in theirdirection of rotation during the mechanical treatment, and when thewings pass the counteredges, the wet tobacco pieces are subjected to asudden heavy impact. The water in the tobacco acts as a hard body, or atleast a body which is firmer than the tobacco mass which has ab sorbedthe water. The rotational speed of the wings shall be chosen in such away (i.e., 1,500 r/m) that the wet tobacco pieces or particles whensubjected to the shock waves arising when the wings or the like pass theprotuberances, counteredges or the like, get no time to change shapeduring the moment of impact proper. As a result the water-soaked tobaccopieces become disintegrated by being exploded from the interior by theimpact effect, if the proportions tobaccozwater are within the rangespecified above.

In a laboratory defibrator of conventional type a suitable time oftreatment is about 4 minutes for a mixture of about 200 grams of tobaccoand grams of water at a rotational speed of 1,500 r/min. of the wings ofthe defibrator.

The proportion of water in the mixture is selected so as not to causesame to gather together into one single lump which will whirl aroundwith the wings.

On the other hand the contents of water must not be so high as in theknown methods discussed in the opening paragraphs of this disclosure,that that mixture becomes fluid and the water acquires a lubricatingeffeet."

It has turned out that grinding between the grinding I plates of adouble milling disk machine also makes the dissolubility of tobacco inwater increase, not to the same extent, however as in a defibrator ofthe kind described above. Such milling disk machines or disk refinersare common in the paper and pulp industry and have disks which areprovided with knives or teeth on. one side. For the purpose of thepresent invention such disks are suitably arranged pairwise with theteeth facing each other. The pattern of the teeth should be chosen insuch a way that the teeth subject the wet tobacco particles to a shockeffect when engaging them. This means that the teeth should besubstantially radially directed. If the teeth of the disks were curvedradially-circumferentially, as is suitable in some other cases, the wettobacco particles would slide along the teeth instead of becomingdisintegrated. When utilizing such disks instead of the defibrator abovereferred to, it is apparently difficult to compress them towards eachother so that the necessary grinding pressure is attained withoutcausing the teeth of the respective disks to cut into each other andcause damage.

The friction heat developed during the heavy mechanical treatmentevaporates part of the water and increases the pressure which increasesthe dissolubility of tobacco in water and. shortens the necessary timeof treatment.

Some kinds of tobacco attain a darker color when heated, and if thecolor is of primary importance, the tobacco should be cooled during themechanical treatment (the grinding). In any case, the tobacco pasteshould be cooled before the tobacco is fed out from the grindingapparatus, since otherwise essential ingredients of the gustatorysubstances should evaporate. When considered advantageous, it is', ofcourse, possible to permit volatile substances to evaporate'inconnection with the grinding;

When tobacco waste is subjected to the heavy mechanical treatment in alaboratory defibrator or milling disk machine, as described in thepreceding paragraphs and in accordance with the invention, under theconditions stated above, the tobacco waste forms horny chips, flakes orother pieces which quite surprisingly have proved to be substantiallydissoluble in water (or a liquid principally consisting of water) toform a solution having more or less prominent adhesive properties.According to the invention, the tobacco pieces resulting from themechanical treatment are subsequently dissolved in water, the ratio byweight tobacco pieces to water preferably lying in the range 1:3 H4 orat least in the range 3:7 1:5. The dissolving of the tobacco lumps orpieces is facilitated through moderate stirring of the mixture of waterand tobacco lumps in the same way as lumps of sugar are dissolved in acup of tea or coffee by means of stirring with a spoon. Any solid, moistresidue in the solution may, at least in respect of tobacco particles,the dimensions of which exceed an acceptable value, be filtered orstrained off and, if so should be considered suitable, which isgenerally the case, be returned to the grinding apparatus to becomesubjected to a repeated mechanical treatment therein together withadditional tobacco waste and liquid. The step of dissolving the tobaccopieces may be carried out either in the grinding apparatus or in aseparate container to which they have been transferred after having beenscraped off the grinding apparatus. The dissolubility of waste tobaccotreated according to the invention is shown in the drawing whichillustrates a tendency diagram of water dissoluble fraction (r) inrelation to the original quantity of the treated tobacco waste, as afunction of the time of treatment (I) at a given, constant shock impulsefrequency.

The tobacco solution thus obtained has a strongly adhesive or bindingeffect and may be utilized in several ways. For example the solution mayby means of moulding, casting, pressing, extrusion or in another mannerknown per se be formed into one or several filamentary or band-shapedwebs or the like e.g., on a steel belt onto which the solution is madeto flow out. The moldability and the method of forming depend on thecontents of water. The tobacco webs may be dried by being subjected to astream of hot air or by radiant heat. Another possibility of utilizingthe tobacco solution is to spray, drop, pour or apply it in another waye.g., onto uncut tobacco leaves, which alternatively may be dipped intothe solution, or onto sheet tobacco which may have been manufacturedaccording to the above. Such application of binder strengthens thetobacco leaves and the sheet tobacco and aids in reducing the amount ofwaste. After that the leaves or sheets have been dried, they are treatedin the usual way, i.e., may either be mixed with leaves and be shredtobecome filler in smokables or be used as binders or wrappers of, bigor small cigars.

By spraying tobacco adhesive onto tobacco in the form of leaves orsemi-manufactured articles the risk of dust rising in the continuedtreatment of the tobacco article is also reduced. The tobacco adhesivemanufactured according to the invention has so great a power of bindingor gluing that no addition of any external binder, such as so calledCMC, which is used at present, is needed. The binding activity is sogreat that it is possible to join together tobacco dust by means of theadhesive.

The embodiments described above are, of course, to be regarded merely asnon-limiting examples and may as to their details be modified in severalways within the scope of the following claims. Thus, it is possible toconvert/homogenize tobacco into a unifonn produce according to theinvention already at a tobacco plantation.

What I claim is:

1. A method of making an adhesive solution consisting principally oftobacco wastes and water comprising the steps of:

a. forming a mixture of said tobacco wastes and water in a containerwith the proportions by weight of tobacco wastes to water being in therange of 3:1 3:7,

b. subjecting the mixture to shock impulses of high repetition frequencyeffected by means of a rotary number rotating in said container relativeto fixed ,abutments whereby chip-like water dissoluble lumps are formedfrom at least a portion of the tobacco wastes,

c. subsequently, separating said lumps from said mixture, and

d. dissolving the water dissoluble portions of said lumps in a secondmixture consisting essentially of said lumps and pure water, and

e. separating said second mixture from undissolved pieces of said lumpsstantially dissoluble chip-like lumps and said lumps are in the range3:1 4:1.

5. Method according to claim 1, including the step of recirculating saidundissolved residual pieces of said substantially dissoluble, chip-likelumps into said mechanical treatment step.

2. Method according to claim 1, wherein the tobacco web is a strip. 3.Method according to claim 1, wherein the formation of the webs includesextrusion of the adhesive.
 4. Method according to claim 1, wherein theproportions between the water used as a solvent for said substantiallydissoluble chip-like lumps and said lumps are in the range 3:1 - 4:1. 5.Method according to claim 1, including the step of recirculating saidundissolved residual pieces of said substantially dissoluble, chip-likelumps into said mechanical treatment step.